If you listen to fans, every OC in the country is terrible and predictable.
DCs tend to get more leeway until their units really poop the bed. I'm not sure why. Maybe they look at it as more the players' fault because you can pinpoint just a few players to blame on each defensive play.
It probably has a lot to do with fans having an idea what kind of play the offense should call on any given play, but fewer fans think much about defensive alignments and rush tactics.
"I can call the play before the snap every time." Well, if you're just calling run or pass, you have a 50-50 shot. And situational calls do have their universal tendencies.
"Why did they go away from x play? They were killing them in the first quarter with it." Do you think maybe the defense adjusted to take it away?